The use of ceramic catalyst carriers having a honeycomb structure for the cleaning of exhaust gases, especially for the cleaning of the exhaust gases of automobiles, has been already known. Such honeycomb structures combine two advantages. On one hand they possess a large surface with respect to a unit volume, on the other the flow resistance through them is very small. The difficulty of their use in devices for the decontamination of exhaust gases of automobiles resides in their required elastic suspension. The pushing forces and vibrations which occur during the travelling of the car, place a heavy mechanical requirement on the honeycomb structure so that finally this will lead to a destruction of the catalyst carrier.
Elastic suspension for such honeycomb structures have been already proposed, such as by U.S. Pat. No. 3,441,382, which describes a catalyst patron which consists of a ceramic monolithic catalyst element placed in a metallic housing and in which, between the catalyst and the housing wall, a heat insulating mass, such as fire resistant brick, or molten aluminum oxide, etc., is placed. By means of a metallic spring, which can be adjusted, a pressure is applied to the insulating mass so that the catalyst body is retained fixedly in its position. Such suspension turned out to be, however, not sufficiently elastic. The pressure applied to the body of the catalyst is too large and is not uniformly distributed in order to be able to prevent a gradual mechanical destruction of the honeycomb structure.
Another device for the catalytic decontamination of the exhaust gases of automobiles has been described in German DAS No. 1,476,507. In such a device the monolithic catalyst is placed in a cylindrical housing between a pair of annular flanges which are in gas-tight connection with the housing. Into the annular gap between the housing and the catalyst a resilient wavy member is placed which can be in form of a corrugated or wavy wire mesh which surrounds the catalyst body very tightly.
The experience of the automobile industry, especially in the case of high revolution four-cycle engines, proves that the wavy-shaped wire mesh inserts cannot withstand the high thermal and mechanical stress even when the wire mesh is made from a high heat-resistant steel. The ceramic body which is embedded in the wire mesh begins to wander around within it when the gripping effect of the wire mesh has lost its original tight application. Then due to the subsequent large shaking and oscillating forces the ceramic body will become quickly destroyed.